On the last Sunday of each liturgical year, the Church celebrates the Solemnity of Our Lord Jesus Christ, King of the Universe, or Christ the King. Pope Pius XI instituted this feast in 1925 with his encyclical Quas primas (“In the first”) to respond to growing secularism and atheism.

The Solemnity of Our Lord Jesus Christ, King of the Universe, commonly referred to as the Feast of Christ the King, Christ the King Sunday, or Reign of Christ Sunday, is a feast in the liturgical year which emphasizes the true kingship of Christ.